1. Field of the Invention
Aspects of the present invention relate to recording transport stream (TS) data, and more particularly, to an apparatus and method for editing program information in order to preserve user data of TS data.
2. Description of the Related Art
Generally, digital broadcast program providers can prevent certain viewers from viewing certain programs by presetting program ratings for each program and including the preset program rating in a transport stream (TS). For example, a rating according to age groups in order to stop minors from viewing adult programs is generally included in the TS. However, even when information about the rating is included in the TS, a viewer may be able to view the program by recording the program and reproducing the program at high speed. The reason is as follows.
FIGS. 1A through 1C are diagrams illustrating one of the conventional syntax structures generally employed in a TS packet for digital broadcast. The conventional syntax structure complies with ISO/IEC 13818-1, alias MPEG 2, which is the standard.
FIG. 1A illustrates elementary streams, ES1 and ES2, including video and/or audio data. Such elementary streams are combined with header information in order to form a packetized elementary stream (PES) packet, as illustrated in FIG. 1B. Also, the PES packets are combined with program information data (such as program and system information protocol (PSIP) data) and then included in a data portion of a TS packet, as illustrated in FIG. 1C. PSIP is an example of program information. Such program information contains auxiliary information required when reproducing a program using the TS packets. PSIP includes a program association table (PAT), a program mapping table (PMT), and an event information table (EIT). The PMT includes a program number, a packet identifier (PID) of TS packets forming the program, and auxiliary information. The PAT includes a program number and the PMT.
When user data (such as a rating) is included in the PMT or EIT of the PSIP, viewing of a program is restricted by the rating even when the recorded program is reproduced at high speed because the PSIP is also parsed during the reproduction at high speed.
However, when the user data (such as the rating) is included in an extended data service (XDS), restricting the viewing of a program by the rating may not be possible. This is because the XDS is included in a video stream (or a PES packet). When the recorded program is reproduced at high speed, part of the video stream is not parsed and reproduced. Accordingly, when the XDS included in the video stream is not parsed/reproduced, it is not possible to restrict a viewing of a program according to the rating.